Engine starter



J. w. FlTZ GERALD 2,356,985

- ENGINE STARTER Filed June 19, 1943 Patented Aug. 29, 1944 I 2,35e,9a ENGINE STARTER John W. Fitz Gerald, dec Wis., by Mary 0. Fit

wauke, Wis., Corporation, Delaware eased, late of Milwaukee, 7 z Gerald, executrix, Milassignor to Briggs '& Stratton Milwaukee, Wis., a corporation of Application June 19, 1943, Serial No. 491,507

6 Claims.

This invention relates to engine starters of the so-called automatic type wherein a pinion is auto matically propelled into and out of mesh with the ring gear of an engine, and has particular reference to engine starters designed for the smaller automobile engines where space is at a premium.

It is always desirable, and particularly in the smaller starters, to obviate the need for a separate pinion stop which ordinarily would be pinned to the shaft of the starter motor. This not only avoids weakening the motor shaft, but enables the starter to be entirely self-contained.

With this in view, it is an object of the present invention to provide a new pinion stop which is incorporated entirely within the structure of the starter itself, but which is so designed that it nevertheless enables the pinion to be as small in size as the diameter of the motor shaft per- Inits.

More specifically, it is an object of this invention to provide a pinion stop located at the rear end portion of the starter and which is so designed as not to interfere with free rotation of the pinion in all the operative stages of the starter.

With a view toward assuring that, the entire starter shall be self-contained, it is, another object of this invention to so construct the starter mechanism that the entire unit is mounted on a tube which in turn may be secured to the shaft of the starter motor, and in this connection it is-a further object of the invention to provide a manner of retaining the various parts assembled 0n the tube with the pinion actuator free on the tube to move as required during the starting function, while in the inoperative state of the starter the pinion actuator is restrained against movement on the tube by stop means carriedon the tube itself.

Still another object of this invention is to provide a starter of the character described wherein a sleeve integral with the pinion and a barrel freely rotatably connected with the sleeve houses the entire mechanism of the starter, so that the external appearance of the starter is neat and all operating parts thereof are adequately protected.

With the above and other objects in View, which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described, and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawing illustrates one complete example of the physical embodiment of the invention constructed in accordance with the best mode so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a side view with parts broken away and in section, of a starter embodying this invention; said view showing the pinion in its retracted position; and V Figure 2' is a view similar to Figure 1, but with the pinion extended and meshed with the ring gear. r Referring .now particularly to the accompanying drawing, the numeral 5 designates the shaft of a motor upon which th starter, indicated generally by the numeral 6, is mounted. The starter is a unitary assembly built around a tube 1 which is adapted to be fitted to the motor shaft as shown.

At its forward end the tube 1 has a stop shoul-v der 8 provided by a spring ring snapped into an appropriate groove in the tube and against which the forward end of an externally threaded pinion actuator 9 engages when the starter is in its inoperative condition'shown in Figure 1.

The pinion actuator 9 carries the pinion member comprising a pinion l0 and an internally threaded sleeve I l integrally connected therewith. The sleeve II has threaded connection with the actuating member 9 so that relative rotation between these parts effects endwise propulsion of the pinion to and from engagement with the engine ring gear I-2.

This operative driving position of the pinion is defined by a novel stop arrangement located atthe rear end of the starter. It consists of a barrel l3 freely rotatably connected to the sleeve II and having a split spring ring M in its outer open end to engage with the flange I5 of a driving collar I6 'fixed to the tube 1 and the motor shaft"5. The free running connection between thepinion sleeve and the barrel is formed by confining an inturned flange of the barrel between shoulders I! and I8 on the sleeve, the latter being a spring ring to enable assembly.

Torque is transmitted to the pinion actuator through a resilient driving connection comprising the flanged collar (which forms a driving part) and a flange ill on the actuating member (which forms a driven part) and between which an elastically deformable annulus 20 is confined.

The parts are of such dimensions that with the pinion actuator engaging its stop 8 as shown in Figure 1, the annulus 20 will be retained under a slight degree of axial precompression so as to establish frictional driving engagement between back against the elastically deformable annulus 20 until the reaction equals the load ofthe engine, whereupon the cranking of the engine takes place.

From the foregoing description, taken in connection with the accompanying drawing, it will be readily apparent to those skilled in the art, that this invention provides a new manner of obtaining the necessary pinion stop which is particularly adaptable for use with small size starters where the pinion must be kept as small as the .required strength of the'motor shaft will permit.

What is claimed as the invention is:-

1. An engine starter comprising: a tube adapted V to be fitted to the shaftof a starter motor; a

shoulder at one end of the tube forming a stoma pinion actuator loose on the tube and engageable with the stop formed by the shoulder; a pinion member having an operative connection with the actuator to be carried thereby with the pinion projecting beyond the tube; a resilient driving connection between the tube and the pinion actuator comprising, a driving part fixed to the tube, a driven part fixed with respect to the pinion actuator, and an elastically. deformable member between said driving and driven parts; and a stop for limitingforward propulsion of the pinion member to its operative driving position comprising a barrel freely rotatably mounted on the pinion member and encircling the resilient driving connection and having a shoulder engageable with a portion of said driving part when the pinion reaches its operative driving position.

2. In an engine starter of the character described: a pinion having an internally threaded sleeve; a pinion actuator on which said sleeve is threaded .so that relative rotation between the actuator and the pinion sleeve effects relative longitudinal motion of said parts; a resilient drive for the pinion actuator including driving and driven parts, the latter being fixedrwith relation to the actuator, and an elastically deformable member connecting said driving and driven parts; and a stop for limiting propulsion of the pinion to its operative position comprising a barrel encircling the resilient drive for the pinion actuator and freely rotatably but nonlongitudinally movably connected with the pinion sleeve, an an abutment on said barrel engageable with said driving part of the resilient drive.

3. In an engine starter of the character described: a tube adapted to be secured on the limiting the forward propulsion of the pinion when the same reaches its operative driving position comprising an abutment engageable with said driving part; and means connecting the abutment with the pinion member.

4. An engine starter of the character described comprising: a tube adapted to be secured on the shaft of a starter motor; a shoulder on the tube; a pinion actuator slidable and freely rotatable on the tube and engageable with said shoulder to have its longitudinal movement limitedthereby in one direction; a driving part fixed to the tube remote from said shoulder; an elastically deformable collar encircling the tube between the driving part and the pinion actuator for resiliently transmitting torque to the pinion'actuator; a pinion member comprising a pinion and a sleeve; and a threaded connection between said pinion sleeve and the pinion actuator whereby relative rotation between said parts propels the pinion to and from its operative driving position, said pinion being at all times beyond the adjacent end of the tube.

5. In an engine starter of the character described: a pinion; a sleeve integrally connected with the pinion and projecting rearwardly therefrom; a barrel freely rotatably connected to the pinion sleeve and projecting rearwardly therebeyond; and mechanism at all times wholly inside the pinion sleeve and said barrel for projecting and retracting the pinion and transmitting a resilient drive to the pinion.

6. In an engine starter of the character described:- a pinion; a sleeve integrally connected with the pinion and projecting rearwardly therefrom; a barrel freely rotatably connected to the pinion sleeve and projecting rearwardly therebeyond; mechanism at all times wholly inside the pinion sleeve and said barrel for projecting and retracting the pinion and transmitting a resilient drive to the pinion, and including a driving part adapted to be secured to the shaft of a starter motor, said driving part having a portion thereof adjacent to the inner wall of said barrel; and a stop projecting in from the inner wall of the barrel and engageable with said portion ofthe driving part for limiting forward propulsion of the pinion in its operative driving position. I

MARY C. FITZ GERALD, Emecutn'a: of the Estate of John W. Fitz Gerald,

Deceased. 

